<?php
    if(isset($_GET['part']))
    {
        if($_GET['part']=='course1')
        {
            include('course-1.php');
        }
        else if($_GET['part']=='course2')
        {
            include('course-2.php');
        }
        else if($_GET['part']=='course3')
        {
            include('course-3.php');
        }
        else if($_GET['part']=='course4')
        {
            include('course-4.php');
        }
        else if($_GET['part']=='course5')
        {
            include('course-5.php');
        }
        else if($_GET['part']=='course6')
        {
            include('course-6.php');
        }
        else if($_GET['part']=='course7')
        {
            include('course-7.php');
        }
        else if($_GET['part']=='course8')
        {
            include('course-8.php');
        }
        else if($_GET['part']=='course9')
        {
            include('course-9.php');
        }
        else if($_GET['part']=='course10')
        {
            include('course-10.php');
        }
        else if($_GET['part']=='course11')
        {
            include('course-11.php');
        }
        else if($_GET['part']=='course12')
        {
            include('course-12.php');
        }
        else if($_GET['part']=='course13')
        {
            include('course-13.php');
        }
        else if($_GET['part']=='course14')
        {
            include('course-14.php');
        }
        else if($_GET['part']=='course15')
        {
            include('course-15.php');
        }
        else if($_GET['part']=='course16')
        {
            include('course-16.php');
        }
        else if($_GET['part']=='course17')
        {
            include('course-17.php');
        }
        else if($_GET['part']=='course18')
        {
            include('course-18.php');
        }
        else if($_GET['part']=='course19')
        {
            include('course-19.php');
        }
        else if($_GET['part']=='course20')
        {
            include('course-20.php');
        }
        else if($_GET['part']=='course21')
        {
            include('course-21.php');
        }
        else if($_GET['part']=='course22')
        {
            include('course-22.php');
        }
        else if($_GET['part']=='course23')
        {
            include('course-23.php');
        }
        else
        {
            include('welcome.php');
        }
    }
    else
    {
        include('welcome.php');
    }
?>